Vehicles such as hybrid automobiles or electric automobiles in many cases include a current detector for detecting a current that flows through a busbar connected to a battery. Examples of apparatuses that may be applied as such a current detector include a magnetic proportion-type current detector and a magnetic balance-type current detector.
A current detector of a magnetic proportion type or a magnetic balance type includes a magnetic core and a magneto-electric conversion element, for example, as shown in Japanese Pub. Patent Apps. H10-104279, 2006-166528A, and 2009-58451-A. The magnetic core is a magnetic material substantially in the shape of a ring with a gap portion, resulting in two ends facing each other across the gap portion. The magnetic core is formed in one piece so as to surround a hole portion penetrated by a busbar. The hole portion of the magnetic material is a space (current detection space) through which a current that is to be detected flows.
In the conventional current detector, the magnetic core has a structure obtained by a plurality of thin plate-like members that each have substantially the shape of a ring and are made from a magnetic material being stacked on top of each other via an adhesive agent. Hereinafter, the magnetic core having such a structure is referred to as a stacked-type magnetic core.
Furthermore, the magneto-electric conversion element is disposed in the gap portion of the magnetic core. The magneto-electric conversion element detects a magnetic flux that changes in accordance with a current that flows through the busbar penetrating through the hole portion, and then outputs a detection signal of the magnetic flux as an electrical signal. Typically, a Hall element is used as the magneto-electric conversion element.